<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <h1 style="position:absolute; left:280px; top:155px; width:auto; height:210px;">你喜欢我吗?</h1>
    <div id="By" style="position:absolute; left:285px; top:235px;">
        <input type="button" value=" 是的！ " onclick="f1()">
    </div>
    <div id="Bn" style="position:absolute; left:360px; top:235px;">
        <input type="button" value=" 喜欢个锤子！ " onmouseover="f()" onclick="f2()">
    </div>
    <script>
        function f1() {
            alert("太好来，晚上一起吃饭看电影！！！")
        }
        var flag = 1;
        function f() {
            var Bn = document.getElementById('Bn');
            var aWidth = document.body.clientWidth || document.documentElement.clientWidth;
            var aHeight = document.body.clientHeight || document.documentElement.clientHeight;
            var sJs1 = Math.floor(Math.random() * aHeight);
            var sJs2 = Math.floor(Math.random() * aWidth);
            if (flag == 1) {
                Bn.style.top = sJs1 + 'px';
                Bn.style.left = sJs2 + 'px';
                flag = 2;

            } else if (flag == 2) {
                Bn.style.top = sJs1 + 'px';
                Bn.style.left = sJs2 + 'px';
                flag = 3;
            } else if (flag == 3) {
                Bn.style.top = 235 + 'px';
                Bn.style.left = 286 + 'px';
                flag = 4;
            } else if (flag == 4) {
                Bn.style.top = 235 + 'px';
                Bn.style.left = 360 + 'px';
                flag = 1;
            }
        }
        function f2() {
            alert('这不是你的真心话！');
        }
    </script>
</body>

</html>